Mercury-vapor lamp



.Oct. 5 1926.

J..NISBET MERCURY VAPOR LAMP Filed Sept. 21 1925 I 4 sheets sheet 1 Oct. 5 1926. 1,602,245

. I J. NISBET MERCURY VAPOR LAMP Filed Sept. 21 1925 4 Sheets-Sheet 2 WVE/V TOR L/Ams /V/J 557" Oct. 5 1926.

. J. NISBET MERCURY VAPOR LAMP Filed Sept. 21

1925 4 Sheets-Sheet i,

I M/YENT'O/fl JAMES N/sggr Oct. 5 1926.

J. NIS-IBIET MERCURY VAPOR LAMP Filed Sept. 21

4 sheets-sheet 4 ILJ IN YEN TOR. JAMEsfl/Wsasr am rm Patented a. 5, 1926.,

I UNITED STATES PATENT OFFICE.

JAMES NISBET, OF GLASGOW, SCOTLAND.

MERCURY-VAPOR LAMP.

. Application filed September '21, 1925, Serial No .According tothis invention I provide a' mercury vapor lamp comprising an outer shell and an inner shell arranged to form a hermetically sealed mercury vapor space therebetween, one of said shells being provided at both ends with a pocket communi' cating with said vapor space and arranged to contain mercury and an electrode in each of said pockets to cause electrical circuits through the mercury at both ends and throughout said sealed chamber.

The two electrodes at opposite ends of the lamp dip into the mercury and thus, when the current is switched on, complete the circuit or circuits vaporizing the mercury, and filling the entire vacuum or gas filled chamher with luminous mercury vapor.

When the current is switched off the vapor is condensed ready for the next operation.

The vapor lamp is here shown as parabolic, but may be of any suitable shape and its back is silvered to act as av reflector or mirror.

The vacuum chamber walls of the body of the lamp may be composed of quartz glass or other suitably annealed glass adapted to stand the temperature. Where the greenish tint of the mercury vapor is desired to be.

eliminated, certain chemicals, such as cadmium and such like may be added to the mercury in the vacuum chamber. Likewise to prevent the mercury or vapor adhering to the electrodes or to the walls of the vac--' uum chamber, zirconia or silica, or other oxides of metal and'gas, such as carbonic acid gas, may also be added in order to counteract any little air or oxy en which might gain access atany time to t \e vacuum chamber.

In order that my invention may be clearly understood and readily carried into eflect,

. 57,757, and in Great Britain September 11, 1924.

I have hereunto appended sheets of draw-- ings, of which: a

Figure 1 is a central sectional view of a mercury vapor lamp constructed in accordance with my invention.

Figure 2 is an elevation of the same.

Figure 8 is a sectional view through the line 3-3 of Figure 1.

Figure 4 is an end elevation of the smaller encl pf the lamp.

Figure 5 is a sec iwh-al view of a modified form of my lamp. i i

Figure 6 is a sectional view of a double shelledsaucer-shaped lamp constructed in accordance with anothermodified form of my invention.

Figure 7 is a sectional view of a double shelled conical-shaped lamp constructed in accordance with another modification of my invention.

Figure 8 is an elevation of a spiral singletube lamp'constructed in accordance with another modification of my invention.

.Figure 9 is a sectional view of a double shelled hemispherical lamp constructed in accordance with another modification of my invention.

Figure 10 is a diagram showing a battery of single walled tubular lamps for surround-- ing the lens P, when reflecting an opaque obiect back through the lens P onto a screen.

igure 11 is a diagrammatic elevation corresponding to Figure 10.

. Figure 12 is a sectional view of a double shelled cylindrical lamp, forming another may be welded to each other at the two I mouth ends and two neck ends respectively. Figure 14 is an elevation of a detachable filler tube, with two stop-cocks and filler mouth for the insertion of mercury without danger of air getting into the tube of the lamp, and may be also used for exhausting sealed space to give a vacuum.

Figure is aside view, partly in section, of a 'modified form of tubular electrode.

Figure 16 is a section taken" on the line 15-15 of Figure 1.

Referring especially to Figures 1, 2, 3, 4 and 16, the lamp comprises a shell A of quartz glass or of any suitable material which is silverized on its exterior surface to act as a reflector and which has contained '1 therein another-shell B consisting of quartz glass or of any other transparent heat resisting material, and held concentric with the outer shell A b means of circular spacing pieces or gas ets C. These circular 20 spacing pieces or gaskets are of renewable heat resisting materials and may or may not be nonconductors of electricity and act as renewable seals at each end of the lamp to keep the vacuum or gas space X between the chambers orshells A and B gas-tight, at the larger and smaller ends. Caps J are screwed onto each end of an outer casing which is arranged on the outer shell A and compresses the spacing pieces or gaskets C between the shells A and B. The spacin pieces or gasketsO and the glass at bot ends of the lamp are slightly tapered thus ensuring, with the addition of a film of cement or plaster of Paris, an air-tight and changeable joint. The inner faces of the gaskets C are rovided with mica discs or washers E an tungstened copper discs or washers E to prevent the electrical arcing affecting the gaskets C and from polarizing 4 or neutralizing the electrodes or from cracking theglass shells.

The outer shell A is enlarged at each end 1 to form a circular pocket D, into each of which ockets D there is inserted an electro de ring E electrically connected to ter minals F at the exterior of the lamp. For.

filling or charging the pockets D with the requisite amount of mercury L and for charging and exhausting chamber space or working it at atmospheric pressure, inlets G are formed in tubes A, the ends of which are extended a'little so that'they may be used as trunnions for supporting the lamp;

The tubes-A are provided on opposite sides of the shell A, the opening and closing of used so as to give cinema with fresh mercury or gases and for working the vapor space at atmospheric pressure, the said gases being blown through one stopcock ant. out at the other, and both stop' .cocks being closed when the air or gas has thus been expelled or exhausted and favorable vacuum formed; or two stop-cocks opened for working vapor space at atmosheric pressure when wanted in space X. lhe stem M of a suitable initial, or auxiliary, electric heating, illuminating and tinting lamp M is adjustably arranged in a bushing 0 provided at the small end of the shell B so as to protect the shell B and a globular condenser V (referred to hereafter) from fracture by i the sudden great heat caused when the electric current or currents are turned on to main circuit of the lamp. Air or liquid cooling circulation into the interior Z of the lamp shell B, Figure 1, and on all double walled lamps, is arranged to take place through passages N in the bushing O, and passages 0 Figures 1 and 16, and the circulation of cooling liquid or air for the outer or inner side of the shell A, or of the enclosed space can also be arranged if required. The globular hollow quartz condenser V is of the thermosiphon type, cooled by circulating cooling liquid and this or other condenser can be projections, with convergent beams of light.

The tubular electrode, for providing an auxiliary supply of mercury vapor, cpmprises according to a modificatitin of my invention, as shown in detail in Figure 15, a frame of two substantially semicircular tubes E which are connected at their. bottom ends by a T-piece E? orelbows, An elbow E is secured to the'other end of the limb E and to" a tube E, projecting through the asbestos gasket C and a tung-- stened copper disc E and mica washer E provided on the inner face of said gasket. A stop-cock H or valve is provided in the tube E and is connected to an elbow-piece E". A tube Eis connected to the T-piece E and extends through the disc E washer E and gasket C, said tube also being furnished with a stop-cock or valve H. Terminal nuts F are screwed onto both the tubes E and E and grip between them the positive or negativelead, as the casemay be, from the electrical supply source.

The tube E is formed, at its upper open end which faces the disc E with a valve seat V with which a valve -V having a screwed stenr V and milled-head V is adapted to cooperate, so as to control the mercury and mercury vapor issuing, when the tubular electrode is connected to the electrical supply sourceg from the tube E and impinging on the tungstened copper disc E. The stop-cocks Hill, are adapted to be used for charging the tubular electrode with mercury, liquids, chemicals or "gases, or for exhausting the electrode, or vapor space sealed chamber, or when working said space at .atmospheric pressure. It will be understoood that when an electrical current flows sideways, between and through the tubulous and channel electrodes, the mercury in the interior and exterior thereof is vaporized and passes in the case of the tubulous electrode through the valve V. ,-V**, and in the case of the channel electrode rises from its upper open side and from its exterior surfaces, thus augmenting, the supply ofvapor from the mercury in the pockets D.

Referring to Figures 5, 10 and 11, the lamp comprises a single walled tube B which is closed at each end by an asbestos gasket C 9 and otherwise as hereinbefore described and with electrodes E at both ends with corresponding terminals, the light passing through. the sides of the single wall annular mercury pockets ,1) and the electrodes. These electrodes have the terminals E". P is the reflection lens, Q, thewall of the lamphouse, and R the picture or, object reflected back through the lens P onto the screen S. The spiral lamp, or lamps, or any four of the double walled lamps, may replace the square battery of single walled lamps round the lens P(see Figures 10 and 11).

Figure 8 shows a spiral single walled tube mercury lamp U, provided with a stop-cock trunnion T at the middle of its length, at right angles to the plane of the coil. The

ends ofthe tube are attached to mercury pockets D which are secured to the two ends of the tube. Stop-cocks and outside tubular terminals H are also provided for facilitating the charging'of the spiral tube with mercury and fresh gas after the gas has been blown through in order to expel the air and for adjusting the mercury level in the pockets D.

An electrode such as herein described is provided in each mercury pocket and connected to the terminals.

The lamps illustrated in Figures 5 and 8 are particularly adapted for use when projecting an opaque object onto a screen. In Figures 10 and 11, for example, four single walled lamps B like Figure 5, are shown arranged square wise around a circular lens P arranged in the wall of the lamp house, or any 4 double walled lamps like Figures 1, 6, 7, 9, 12 and 13 may be used for opaque reflection. The object R to be reflected is arranged at-the back of the lens P, while 1 C the mercury thereof, the image of the object R being projected by the lens onto the screen S.

When the spiral lamp U,'in Figure 8, is

used, the .lens P is arranged in the center thereof, as shown.

shown in Figure-6 t e gaskets between the inner a-nd outer shells are indicated-at C the mercury pockets at D? and the electrodes at E. I

In the conical form of my lamp shown in.

Figure 7,, the inner and outer shells are respectively indicated at A, B", the gaskets at pockets at'D and the electrodes at E,

In the saucer-she. ed form of" the lamp In Figure 9 I show a lamp of hemispherical form in which the innerrand'outer shells are respectively indicated at A B", the gaskets at C, the mercury pockets at D", the electrodes at E, the space between the shells at X and the space within the inner shell at ZR,

In the cylindrical form of my lamp shown in Figure 12, the inner and outer shellsare respectively indicated at A3 B, the kets at C", the caps at J", the mercury pockets at D, the mercury, at L ,-the' inlets at G, the electrodes at E and 'the;

terminals at F The space between the shells is indicated atX and the space'within the inner shell at Z.

Supplementing the brief description of;-

Figure 13, the mercury pockets are indi catedat D the electrodes at E3. In this form of theinvention the/electrodes are indicated as tubular and (me of them is shown provided with an inlet E and a" stopcock E W The stop-cocks G, H are adapts to be used for charging the-electrode"wi h mer- Fcui'y liquids, chemicals or gases, or for use when exhausting the electrode, or vacuum s ace-or when workin said s ace at atmospheric pressure. The detachable tube G Figure 4, may be used for, this purpose and is also adapted to be connected to the vertical limb of the elbow E Figure 15. will be understood that the electrical current flowing through the channel and tuthe'interiorthereof a-swell as'lhat at the exterior, the mercury vapor from the interior of the tubulous electrode passing through the valve V V and vapor also rising from the open: top side of bottom bulous electrodes ,vaporizes -th*e;me'rcury in of the lamp, ensures that the whole of the a large intervening space X will be filled space.

with the luminousmercury vapor, so that the light will be extremely brilliant. The lamp may also be turned to any position about its axis owing to the annular pockets "D and the electrodes E retaining the requi- The supply of vapor from said tubulous electrode can be readily regulated by means of the valve V Said tubular and terminal electrode may also be used for supplying mercury to theinterior of the lamp, or when working lamp at atmospheric pressure.

The trunnions with their stop-cocks H and H may be carried by gimbal rings so as to give a universal movement to each of the lam s. Hliving thus described my invention, What I claim is:

1. A mercury vapor lamp comprising, in combination, an outer shell and an inner shell arranged to form a hermetically sealed mercury vapor space therebetween, means at both ends of the outer shell, in communication with said space and adapted to contain mercury, and electrode means at each end of said'lamp and in said mercury containing means for causing an electrlc circultthrough the mercury and electrodes sidewise at each end, and through said sealed space, whereby the mercury is vaporized and said space sealed with luminous mercury vapor.

2. A mercury vapor lamp as in claim 1 in which said-outer shell is provided with conduits communicating with the mercury vaporspace and each provided with a valve. i

3. A mercury'vapor lamp as in claim 1 in which the means'at both ends of the outer shell for containing mercury is an annular pocket at each end of said shell and which communicates with the mercury vapor 4. A mereuryfvapor lamp as in claim 1 in which the means at both ends of the outer shell for containing mercury is an annular nocket at each end of said shell and which communicates with the mercury vapor spaife, and in which Leach electrode 'is also annular in form and is arranged in one of a the pockets 5. A mercury vapor lamp as in claim 1 in which said outer shell-isprovided with con duits communicating with the mercury vapor space and each provided with a valve,

and in which a filler tube is provided for attachment to either of said conduits and is provided with a funnel and with controlling valves.

6. A mercury vapor lamp comprising, in combination, an outershell and an innershell arranged in spaced relation, gaskets between the ends of said shells, forming end closures for said shells and coacting with said shells to form a hermetically sealed mercury vapor space therebet-ween, one of said i extending through said bushing, and an elec-- trode in each of said pockets, said pockets and said electrodes being annular in form.

.8. A mercury vapor lamp comprising an inner shell and an outer shell arranged in spaced relationto form a mercur' vapor space therebetWeen said outer shel being provided with an annular mercury containmg pocket in each end and communicating with said space, and a casing arranged in spaced relation to the outer shell and having its ends fitted on the outer walls of said pockets, and an electrode in each of. said pockets. a g v 9. A mercury vapor lamp comprising an inner shell and an outer shell arranged in spaced relation, said outer shell having an annular mercury containing pocket at each end, gasketsforming closures for the ends of said 'shells'and coacting therewith to form a mercury vapor space between the shells, said gaskets bearing against the inner spaces of the outer walls of said pockets, a casing arranged in spaced relation to the outer shell and having its ends arranged on the outer walls of said pockets, and capson the ends of said casing, said shells and the outer sides of said gaskets. and an electrode in each pocket, said electrodes being connected to a and carried by said gaskets.

mercury vapor lamp having an 10. A inner shell and an outer shell arranged to form a mercury vapor space therebetween, one of said shells aving a mercury containing pocket at each end, an electrode in each pocket, an auxiliary electric lamp in the inner shell'and means to initially heat the outer shell.

11. A mercury vapor lamp comprising inner and outer shells arranged in spaced relation to form a mercury vapor space therebetween and one of said shells having van annular pocket at each end, an annular electrode in each pocket, an auxiliary electric lamp in the inner shell and a lens at one end of the inner shell.

12. A mercury vapor lamp arranged to form a mercury vapor space therein and provided at each end with an annular mercury containing pocket and an annular electrode in each of said pockets I 13. A mercury vapor lamp arranged to form a mercury vapor space therein and prm inlets and also with an outlet for mercury vapor therefrom and with a valve to control said outlet.

In testimony whereof I alfix my signature.

JAMES NISBET. 

